A novel oxidative stress marker in contrast-induced nephropathy; can dynamic thiol/disulfide homeostasis be a predictive marker for elderly patients?

Aim: The aim of this study was to examine if dynamic thiol/disulfide homeostasis is a predictive marker for contrast-induced nephropathy for the first time in literature. Also, we aimed to investigate effecting factors for contrast-induced nephropathy in hospitalized elderly patients. Materials and methods: A total of 39 patients who administered contrast media were included in the study; 9 developed contrast-induced nephropathy after the intervention, and the other 30 did not develop; matched for age, gender, and baseline-48 hour creatinine and native thiol, total thiol, disulfide values were recorded. Additionally, antioxidant parameters were compared with other clinical parameters within a comprehensive geriatric assessment. Results: In the contrast-induced nephropathy (CIN) group, native and total thiol levels decreased, and disulfide levels increased at 48 hours, but it was not statistically significant. Patients with CIN had a significantly higher level of neutrophil-to-lymphocyte ratio (p=0.032) than non-CIN patients. Serum albumin, folic acid, Katz Activities of Daily Living (ADL) score, and Mini Nutritional Assessment (MNA) score levels correlated with serum native thiol values in all patients, and a significant inverse correlation was found between native thiol and C-reactive protein and ferritin. Total thiol levels correlated with lymphocyte count, albumin, Katz ADL score, and MNA score in all patients, and there was a significant inverse correlation between total thiol and CRP value. Conclusions: This study demonstrated that antioxidant reserve is reduced by acute inflammation and induced by nutrition and functionality in elderly patients. In the light of this study relationship between antioxidant status and CIN can be examined in the elderly in further large, prospective, multicenter studies. Keywords: Contrast-induced nephropathy, elderly, oxidative stress, antioxidants